1. Field of the Disclosure
Embodiments of the present disclosure relate to an input device which includes an operation surface, an operation position detection unit, such as a capacitive sensor, and a pressing detection unit, such as a mechanical switch, and, in particular, to an input device in which input sensitivity for a planar direction is adjusted in an area which is a part of the operation surface and in which a pressing operation is frequently performed.
2. Description of the Related Art
An input device disclosed in Japanese Unexamined Patent Application Publication No. 2007-304757 includes an input pad which is provided in front of a keyboard input device. When the operation surface of the surface of the input pad is operated using a finger, it is possible to detect the operation position thereof using, for example, a capacitive sensor which is set in the input pad. In addition, it is possible to vertically move the input pad, and a pressing detection switch is provided at the lower part of the input pad. Therefore, when the input pad is pressed downward, the pressing detection switch is turned on, and thus it is possible to detect a pressing operation.
In the input device, if a finger touches the operation surface and operates in the planar direction, a finger operation position signal is output by the capacitive sensor, and a control unit outputs a sliding operation input signal based on the operation position signal. An electronic apparatus equipped with an input device performs, for example, an operation process of moving a cursor on a display screen based on the sliding operation input signal.
The whole area of the operation surface can be used as an operation position detection area using a capacitive sensor, and the whole area of the operation surface is set as an area on which the pressing operation can be performed. Further, if the operation surface is pressed downward by the finger, the pressing detection switch is switched into an ON state. If the pressing detection switch is turned on, the control unit outputs a pressing operation input signal. The pressing operation input signal is generated which is the same as an input signal acquired when an L button or an R button, which is provided in parallel in a mouse or an input pad according to the related art, is pressed.
As shown in FIG. 11, an operation surface 1 is divided into a pressing operation area 1a on which a pressing operation is frequently performed and an area 1b on which a sliding operation is frequently performed. As shown in FIG. 11, if the pressing operation area 1a is pressed downward by a finger F, a pressing detection switch is turned on, and thus a pressing operation input signal is output.
However, if the finger F unintentionally performs sliding movement while pressing the area as shown using a dotted line in FIG. 11, the sliding movement of the finger F is detected by a capacitive sensor, and thus the control unit outputs a sliding operation input signal. As a result, there is a case in which an incorrect operation, such as an unintended cursor movement on a display screen, is generated. In addition, even when the finger F does not move, the contact area of the finger F and the operation surface 1 becomes large due to a pressing operation, and thus there is a case in which the capacitive sensor outputs erroneous detection results for the variation in the contact area as if the finger performs sliding movement, and the control unit outputs a sliding operation input signal.
In addition, as shown in FIG. 12, there is a case in which an operation is performed by placing a plurality of fingers F1 and F2 on the operation surface 1. In FIG. 12, the first finger (thumb) F1 is present on the pressing operation area 1a and the second finger (index finger) F2 is present on the sliding operation area 1b. In FIG. 12, a pointer movement operation is performed in which the first finger F1 is placed on the pressing operation area 1a and the second finger F2 is caused to perform the sliding movement on the sliding operation area 1b. 
However, there is a case in which the first finger F1 unintentionally performs the sliding movement together with the sliding movement of the second finger F2. At this time, the sliding movement of the first finger F1 is detected by the capacitive sensor, and thus the control unit outputs a sliding operation input signal for the first finger F1. As a result, there is a case in which an incorrect operation, such as the display of a pointer movement which is different from an intended pointer movement or an unexpected gesture on the display screen, is generated.
In particular, when an operation is performed using the plurality of fingers F1 and F2 as shown in FIG. 12, it is easy for the amount of unintended sliding movement of the first finger F1, which is positioned in the pressing operation area 1a, to be large, compared to a case in which an operation is performed using a single finger F as shown in FIG. 11.
These and other drawbacks exist.